[resolved upstream] Mnemosyne fails to start in Yakkety due to missing PyQt4-WebKit

[David Oftedal]

Mnemosyne fails to start in Yakkety due to a failure to import QtWebKit.

Traceback (innermost last):
  File "/usr/bin/mnemosyne", line 155, in <module>
    debug_file=options.debug_file)
  File "/usr/lib/python2.7/dist-packages/mnemosyne/libmnemosyne/__init__.py", line 164, in initialise
    self.register_components()
  File "/usr/lib/python2.7/dist-packages/mnemosyne/libmnemosyne/__init__.py", line 215, in register_components
    exec("from %s import %s" % (module_name, class_name))
  File "<string>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/mnemosyne/pyqt_ui/review_wdgt.py", line 5, in <module>
    from PyQt4 import QtCore, QtGui, QtWebKit
 ImportError: cannot import name QtWebKit

Searching with apt-cache reveals that there is a QtWebKit based on Qt4:

python-pyqt5.qtwebkit - Python 2 bindings for Qt5's WebKit module
python-pyside.qtwebkit - Qt 4 WebKit module - Python bindings
python3-pyqt5.qtwebkit - Python 3 bindings for Qt5's WebKit module
python3-pyside.qtwebkit - Qt 4 WebKit module - Python3 bindings

... but installing it manually doesn't prevent the above error:

Traceback (innermost last):
  File "/usr/bin/mnemosyne", line 155, in <module>
    debug_file=options.debug_file)
  File "/usr/lib/python2.7/dist-packages/mnemosyne/libmnemosyne/__init__.py", line 164, in initialise
    self.register_components()
  File "/usr/lib/python2.7/dist-packages/mnemosyne/libmnemosyne/__init__.py", line 215, in register_components
    exec("from %s import %s" % (module_name, class_name))
  File "<string>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/mnemosyne/pyqt_ui/review_wdgt.py", line 5, in <module>
    from PyQt4 import QtCore, QtGui, QtWebKit
 ImportError: cannot import name QtWebKit

[Peter Bienstman (peter-bienstman)]

You need to upgrade to Mnemosyne 2.4 (currently in beta, see our google groups forum) for Qt5 support

[David Oftedal (rounin)]

This bug doesn't concern Mnemosyne 2.4, though, it concerns the package that's available from Ubuntu repositories in Ubuntu 16.10.
That package doesn't work when installed on the system.

[David Oftedal (rounin)]

See also:
https://bugs.launchpad.net/ubuntu/+source/anki/+bug/1633737 Anki fails to start in Yakkety due to missing QtWebKit
https://bugs.launchpad.net/ubuntu/+source/spyder/+bug/1620300 Spyder won't start

[David Oftedal (rounin)]

"Some PyQt4 applications fail to start in Yakkety due to missing QtWebKit"
https://bugs.launchpad.net/ubuntu/+source/python-qt4/+bug/1633819

[David Oftedal (rounin)]

Temporary fix:

1. Add the Xenial repositories to /etc/apt/sources.list

deb http://archive.ubuntu.com/ubuntu/ xenial universe
deb http://archive.ubuntu.com/ubuntu/ xenial-updates universe

2. apt-get update

3. Install older version of PyQt4

apt-get install python-qt4=4.11.4+dfsg-1build4 python-qt4-sql=4.11.4+dfsg-1build4

[themusicgod1 (themusicgod1)]

According to

http://stackoverflow.com/questions/37604532/python-2-7-11-importerror-cannot-import-name-qtwebkit-kali-linux-debian-8

an alternative to including an older version of PyQt4 is a code change in this older version of mnemosyne to Qt5.

[David Oftedal (rounin)]

Thanks, themusicgod1! That seems like a nice fix as well.

[themusicgod1 (themusicgod1)]

@david: easier said than done. There are hundreds of these little changes and a few bigger changes between Qt4->5, including

* a change to the way that "slots" work that is not very intuitive to transfer over how the code works mnemosyne/pyqt_ui/ui_main_wdgt.py

* there's a binary blob in mnemosyne/pyqt_ui/mnemosyne_rc.py that server knows what it's going to take to convert it

* For some reason 'question' isn't getting defined in ReviewWdgt, but maybe that's just my particular changes that are doing this(?)

[Peter Bienstman (peter-bienstman)]

It's a waste of time trying to convert Mnemosyne 2.2.1 to Qt5 when that work has already been done in Mnemosyne 2.4 (took me several months).

It's probably a better idea to work on packaging 2.4, currently in beta.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "Work in progress, this does not actually run" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Flames_in_Paradise (ellisistfroh-deactivatedaccount)]

@ Peter Bienstmann: That's good news, hope you dont mind me providing the link -

https://groups.google.com/forum/#!topic/mnemosyne-proj-users/Et6uWBbFRjU

Title: Mnemosyne 2.4 beta 1 released (13.Oct 2016)

Wonderful software by the way.

[Daniel Holbach (dholbach)]

It looks like the patch is not ready yet, right? Also can you generate the patch using "diff -ruN"?

Can somebody look into packaging 2.4 beta1 as suggested above? That might be easier than redoing the port.

Until a decision has been reached here, I'll unsubscribe the 'ubuntu-sponsors' team for now.

[themusicgod1 (themusicgod1)]

yeah not even close to ready.

[Flames_in_Paradise (ellisistfroh-deactivatedaccount)]

pls confirm/support LP-bug #1650808 (new Verson 2.4) – transferred the debian-bug-ref to there.

[themusicgod1 (themusicgod1)]

According to #1650808, that change trades off the dependence upon PyQt4-WebKit (which doesn't exist in yakkety) with a dependence on QtWebEngine (which doesn't exist in yakkety)